Our invention relates to function control apparatus, and particularly to function control apparatus for producing improved outbound and inbound messages for controlling radio communication systems.
Radio communication systems, particularly those having a command or base station and one or more controlled stations, such as mobile stations, are expected to provide many functions over and above the simple call and answer voice communication, and are expected to establish voice communication quickly and reliably on one of several frequencies or channels. An example of a provided function is where a base station needs to determine the status or condition of a particular mobile station in the system. An example of establishing voice communication is where one of several radio frequencies or channels is to be used for voice communication between two stations in a given system. In order to provide these functions, binary control signals are desirable because of their speed and accuracy. However, when such signals are used at radio frequencies, they are subject to interference, or noise, or fading. While there is function control apparatus available for use with radio communication systems, the speed and reliability of such apparatus are not as high as some users require or prefer.
Accordingly, a primary object of our invention is to provide new and improved function control apparatus for producing outbound and inbound binary messages that permit rapid and reliable synchronization between radio stations.
Another object of our invention is to provide new and improved function control apparatus that produces outbound and inbound binary messages that are relatively free from interference, noise, and fading.
Another object of our invention is to provide new and improved function control apparatus for producing outbound control messages and inbound response messages; both messages having a binary format that permits relatively quick and reliable synchronization between spaced radio stations, and that is relatively immune from the effects of interference, noise and fading when transmitted over radio frequencies.
Another relatively specific object of our invention is to provide apparatus for producing outbound and inbound messages having a new and improved binary format that is particularly useful and desirable in controlling radio communication systems.